Question

The chemical shift of the CH3 protons in diethylether is δ = 1.16 and that of the CH2 protons is 3.36. What is the difference in local magnetic field between the two regions of the molecule when the applied field is (a) 1.9T, (b) 16.5 T?

Answer 1

Answer:

Where Blocal = local magnetic field between the two regions of the molecule

Blocal = (1-σ)B0

ΔBlocal = (1-σ1)B0 - (1-σ2)B0 = (σ2 - σ1)B0 = ΔσB0 ≈ ΔδB0 x 10∧-6

= (3.36-1.16) x 10∧-6 x B0 = 2.20 x 10∧-6B0

(a) ΔBlocal = 2.20 x 10∧-6 x 1.9T = 4.2 μT

(b) ΔBlocal = 2.20 x 10∧-6 x 16.5T = 36.3 μT

Explanation: